1. Field of the Invention
The present invention relates to a tub assembly and a washing machine including the same, more particularly, to a tub assembly which can be manufactured without any difficulties in spite of a front tub having a complex structure.
2. Discussion of the Related Art
In general, a washing machine is an appliance which performs washing through a washing, ringing, spinning and drying cycle to separate dirt from clothes, cloth items and beddings (hereinafter, the laundry) by using wash water, detergent and mechanical action.
FIG. 1 is a sectional view illustrating a drum type washing machine having a conventional tub assembly mounted therein and FIG. 2 is an exploded perspective view illustrating the tub assembly according to the related art.
The conventional drum type washing machine, as shown in FIG. 1, includes a cabinet 1 for defining an exterior thereof, a tub assembly 4 shock-absorbingly mounted within the cabinet 2 for holding wash water and the laundry, and a motor 6 mounted in rear of the tub assembly 4 for transmitting power to the tub assembly 4.
A water supply hose 8, a water supply valve 10 and a detergent supply part 12 are provided in an upper portion of the tub assembly 4. A water drain pump 14 and a water drain hose 16 are provided in a lower portion of the tub assembly 4.
The tub assembly 4 is shock-absorbingly mounted in the cabinet 2 by an elastic member 17 and a damper 18. The tub assembly 4 includes a tub 20 for holding wash water, a drum 30 rotatably mounted within the tub 20 for holding the laundry therein and plural lifters 32 fastened to an inner surface of the drum 30 for lifting the laundry to a predetermined height and dropping the laundry by its gravity. Also, plural through holes 30B are formed on the drum 30 for allowing wash water to pass there through.
Here, the tub 20 is injection-molded with plastic and includes a front tub 22 for defining a front part thereof, a rear tub 24 fastened to a rear portion of the front tub 22 for defining a rear part thereof.
The front tub 22 has a rear portion with an opened surface and an entrance 22A formed on a front surface for allowing the laundry to pass there through. Also, the rear tub 24 has a front portion with an opened surface and a rear portion having a rotation shaft 34 of the drum 30 to pass there through. A bearing housing 26 is formed as one body with the rear portion of the rear tub 24 for rotatably supporting the rear portion of the rear tub 24.
The rear portion of the front tub 22 and the front portion of the rear tub 24 are fixedly fastened by plural fastening members 42 in a state where a seal 40 is provided to prevent water leakage.
Thus, a sealing recess 28 is formed in the rear portion of the front tub 22 and the front portion of the rear tub 24 for installing the seal 40 therein. Plural fastening holes 29 are facing each other along a circumference for fastening the fastening member 42 thereto.
The drum 30 is made of metal sheet and includes an entrance 30A formed in a front portion thereof to communicate with the entrance 22A of the tub 20 and a spider 36 mounted to a rear portion thereof for fixing the rotation shaft 34 thereto.
A manufacturing process of the conventional tub assembly according to the related art will be described.
First, the front tub 22 and the rear tub 24 of the tub assembly 4 are injection-molded with plastic, and the drum 30 is molded with metal sheet.
At that time, the bearing housing 26 is inserted in the rear portion of the rear tub 24 and injection-molded, or fixed by an auxiliary fastening structure.
The spider 36, where the rotation shaft 34 of the drum 30 is formed, is fixedly fastened to the rear portion of the drum 30 and the plural lifters 32 are fixedly fastened to the inner circumferential surface of the drum 30.
The rear portion of the drum 30 is inserted in the rear tub 24 so that the rotation shaft 34 is inserted in the hole formed in the bearing housing 26.
The seal 40 is arranged in the sealing recess 28 formed in the front portion of the rear tub 24. The rear portion of the front tub 22 is closely contacted with the front portion of the rear tub 24 so that the front portion of the drum 30 is inserted in the front tub 22.
At that time, the position of the front tub 22 and the rear tub 24 are adjusted to fasten the fastening member 42 to the plural fastening holes 29, such that the rear portion of the tub 22 is in communication with the plural fastening holes 29 formed in the front portion of the rear tub 24.
The front tub 22 and the rear tub 24 are securely fastened by the fastening member 42 and sealing efficiency of the seal 40 is secured.
However, the conventional tub assembly of the drum type washing machine according to the related art has a problem of increased work time as well as high production cost in manufacturing the tub assembly, because the seal 40 is provided between the front rub 22 and the rear tub 24 and, after that, the fastening member 42 is fastened to the plural fastening holes 29.
Furthermore, there may be another problem that the seal 40 is missed by a worker's mistake or provided insecurely, and still another problem that the fastening member 42 is mis-assembled to deteriorate the secure fastening.
Still further, if the seal 40 is missed or insecurely provided, there may be still another problem that the front tub 22 and the rear tub 24 are severely vibrated to be damaged, or wash water is leaked between the front tub 22 and the rear tub 24.
Especially, since the sealing recess 28 having the seal 40 fastened thereto and the fastening hole 29 having the fastening member 42 fastened thereto are formed in the rear portion of the front tub 22 and the front portion of the rear tub 24, the fastening portion between the front tub 22 and the rear tub 24 should have a too much complex structure.